Cap body of beverage container

ABSTRACT

There is provided a cap body of a beverage container where a large amount of beverage in a container body doesn&#39;t flow out, and a lid member is not vigorously released even if hot beverage is put in the container, and where a degree of freedom to select a spring is improved by alleviating impact force in an opening operation, the cap body of the beverage container comprising: a cylindrically-shaped drinking mouth member releasably provided in a mouth portion of a container body; a lid member connected to the drinking mouth member via a hinge axis; a spring for urging the lid member to the opening direction; and a lock member provided in a position against the hinge axis of the drinking mouth member for maintaining the lid member in a closing state, wherein the drinking mouth member comprises a drinking mouth formed in the lock member side of a peripheral wall of the upper opening; a bottom wall where hinge axis side is made higher than the drinking mouth side; a liquid hole formed in the drinking mouth side and an air hole formed in a hinge axis side on a connection line between the hinge axis side and the lock member side, and the lid member comprises an inner cap provided with a seal member for sealing the liquid hole and the air hole, and furthermore, a shoulder member provided in the container body is connected to the lid member and the hinge axis, and the hinge axis supporting portion of the shoulder member is provided with a protrusion portion to which the lid member slidably contacts in an opening operation of the lid member.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a cap body of a beverage container capable of directly drinking beverage in a container body by opening a lid with a touch.

[0003] 2. Description of the Prior Art

[0004] For example, a cap body disclosed in Japanese laid-open publication No. Hei 9-299253, which is cylindrically shaped and is releasably provided in a mouth portion of a container body, comprises a lid member connected via a hinge axis for opening and closing an upper opening, a spring for urging the lid member to the opening direction, and a lock member provided in a position diametrically against the hinge axis for maintaining the lid member in a closing state. The cap body is formed with a liquid-pouring passage in a distance from an inlet opening opened to an inside of the container body to an outlet opening reaching an upper opening. When the lock of the lid member is released, the lid member is opened by urging force of the spring, thereby it is possible to directly drink beverage in the container by setting one's lips to an peripheral wall of an upper opening of a drinking mouth member.

[0005] However, in the above-mentioned constructions, since a diameter of the inlet opening of the liquid-pouring passage is large, especially when user tries to drink beverage by inclining the container body while getting on a vehicle, there exists such a problem that a large of amount of the beverage in the container flows out due to vibration or the like, to thereby soil user's clothes. Furthermore when hot beverage is put in the container, since an inlet opening area of the liquid-pouring passage is large, there exists such problem that a pressure applied to an inner cap of the lid member blocking the inlet opening becomes larger and then the lid member is vigorously released when the lock member is pressed. Moreover, in order to cope with the pressure applied to the lid member, strength and accuracy of the lock member are required.

[0006] Furthermore, if the urging force of the spring is strong when the lock member of the lid member is released while user is holding the container body, there exist such problems that the lid member is vigorously opened to clash into a shoulder member of the cap body to thereby make user feel unpleasant impact on its hand or to make user feel unpleasant clash sound. If such clash is repeatedly occurred, there is such problem that an impact load is applied to a hinge axis supporting portion of the cap body, thereby the hinge axis supporting portion is damaged due to its long-time use. In addition, since the container body becomes lighter as the beverage in the container diminishes, the container body is shaken by an impact force to thereby fall down. On this account, it is necessary to consider a weight of the lid and a weight/height of a container body, particularly an impact force when the container body is empty, in selecting a spring. Thus, there exist such problems that it can't help selecting a spring having a limited urging force and a selection range of the spring becomes narrower. To the contrary, when the urging force of the spring is weak, there are such problems that the lid member is not sufficiently opened or the lid member slopingly opened for drinking falls down due to its weight.

SUMMARY OF THE INVENTION

[0007] Therefore, the objective of the present invention is to provide a cap body of a beverage container where a large amount of beverage in a container body doesn't flow out due to vibration or the like, and the lid member is not vigorously released even if hot beverage is put in the container, and where a degree of freedom to select a spring for opening the lid member is improved by alleviating impact force in an opening operation of the lid member.

[0008] In order to achieve the above-mentioned objective, according to the present invention, there is provided a cap body of a beverage container comprising: a cylindrically-shaped drinking mouth member releasably provided in a mouth portion of a container body; a lid member connected to the drinking mouth member via a hinge axis for opening and closing an upper opening of the drinking mouth member; a spring for urging the lid member to the opening direction; and a lock member provided in a position against the hinge axis of the drinking mouth member for maintaining the lid member in a closing state, wherein the drinking mouth member comprises a drinking mouth formed in the lock member side of a peripheral wall of the upper opening; a bottom wall where the drinking mouth side thereof is made lower and the hinge axis side thereof is made higher; a liquid hole formed in the drinking mouth side and an air hole formed in a hinge axis side on a connection line between the hinge axis side of the bottom wall and the lock member side; and the lid member comprises an inner cap provided with a seal member for sealing the liquid hole and the air hole. Furthermore, according to the present invention, it is preferred that an uppermost margin of the drinking mouth is formed in an uppermost position of an upper peripheral wall of the drinking mouth member.

[0009] In addition, according to the present invention, there is provided a cap body of a beverage container comprising: a cylindrically-shaped shoulder member releasably provided in a mouth portion of a container body; a lid member for opening and closing an opening portion of the shoulder member; a hinge axis being inserted into a hinge-axis supporting portion of the shoulder member and a hinge-axis receiving portion of the lid member; a spring provided in the hinge axis for urging the lid member to the opening direction; and a lock member provided in a position diametrically against the hinge axis for maintaining the lid member in a closing state, wherein at least one of the hinge axis supporting portion or the hinge axis receiving portion is provided with a protrusion portion to which the lid member or the shoulder member slidably contacts, in an opening operation of the lid member. In the cap body thus constructed, it is preferred that the protrusion portion is such formed that a radial dimension thereof becomes gradually larger toward the opening direction of the lid member, and slidable contact between the protrusion portion and the lid member or the shoulder member is linear contact, and slidable contact area between the protrusion portion and the lid member or the shoulder member increases together with an opening operation of the lid member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which:

[0011]FIG. 1 is a cross-sectional view of the first embodiment according to the present invention in a state where a cap body is opened;

[0012]FIG. 2 is a cross-sectional view of the first embodiment according to the present invention in a state where the cap body is closed;

[0013]FIG. 3 is a plane view of the fist embodiment according to the present invention in a state where the cap body is opened;

[0014]FIG. 4 is a cross-sectional view of the second embodiment according to the present invention in a state where a lid member is opened to slidably contact on a protrusion portion;

[0015]FIG. 5 is a perspective view of an upper back side of the beverage container showing the protrusion portion of the second embodiment according to the present invention;

[0016]FIG. 6 is an upper cross-sectional view of the beverage container according to the present invention;

[0017]FIG. 7 is an upper front perspective view of the beverage container according to the present invention in a state where the lid member is opened;

[0018]FIG. 8 is a cross-sectional view of the third embodiment according to the present invention in a state where a lid member is opened to slidably contact on a protrusion portion;

[0019]FIG. 9 is an upper side view of the beverage container showing the protrusion portion of the fourth embodiment according to the present invention; and

[0020]FIG. 10 is a perspective view of an upper back side of the beverage container of the fourth embodiment according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the present invention will be explained in detail based on the drawings of the first embodiment where a cap body of a beverage container has metallic dual heat-insulating constructions. A beverage container 1, of a size capable of holding with one hand, comprises a container body 2 of a heat-insulating construction, a cap body 3 releasably mounted in a mouth portion of the container body 2. Since the container body 2 is such constructed that an metallic inner container 21 and an metallic outer container 22, whose upper portions are opened, are integrally joined at upper ends thereof, and a heat-insulating portion 23 of a vacuum heat-insulating construction is provided between the containers 21, 22. Furthermore, the outer periphery of the mouth portion of the container body 2 is formed with a screw portion 24 for threadably connecting the cap body 3.

[0022] The cap body 3 comprises a cylindrically shaped drinking mouth member 4 releasably provided in the mouth portion of the container body 2 and a lid member 6 for opening and closing an upper opening of the drinking mouth member 4. The drinking mouth member 4 comprises a cap body receiving portion 41 formed as a bottomed-cylindrical shape, and an attaching portion 42 assembled with the cap body receiving portion 41 for being connected to the container body 2. The lid member 6 is connected to one side of the attaching portion 42 via a hinge axis 5 and is urged to the opening direction by a torsion spring 7 wound on the hinge axis 5. The torsion spring 7 has a spring force to rotate the lid member 6 at an angle of more than 180° from its closing state and to maintain the lid member 6 at such rotated position. Furthermore, a lock member 8 for maintaining the lid member 6 in a closing state by hitching a tip end of the lid member 6 is provided in a position diametrically against the hinge axis 5 of the attaching portion 42.

[0023] The cap body receiving portion 41, in the lock member 8 side of an upper opening peripheral wall, comprises a drinking mouth 43 which is such formed that the peripheral wall of the lock member 8 side is made higher than the peripheral wall of the hinge axis 5 side. The uppermost margin of the drinking mouth 43 is formed in the uppermost position of the upper peripheral wall. Furthermore, there is provided in a lower inner side of a cylindrical body of the cap body receiving portion 41 a bottom wall 44 where the drinking mouth 43 side thereof is made lower and the hinge axis 5 side thereof is made higher. In the bottom wall 44, there are respectively provided a liquid hole 45 in the drinking mouth 43 side and an air hole 46 in the hinge axis 5 side on a connection line between the hinge axis 5 side and the lock member 8 side, to form a liquid passage 47 from the bottom wall 44 to the upper opening. Moreover, the outer periphery of the lower cylindrical body of the cap body receiving portion 41 is provided with a packing 48 for adhering closely to the inner peripheral wall of the mouth portion of the container body 2. The inner periphery of the attaching portion 42 is formed with a screw portion 49 threadably engaging the screw portion 24 of the container body 2.

[0024] The lid member 6 comprises a lid portion 61 for covering the upper opening of the cap body receiving portion 41 and an inner cap 62 provided in the lid portion 61 to be inserted into the liquid passage 47. The inner cap 62 is provided with a seal member 63. The seal member 63 results from integrally forming a flowing-out side seal portion 64 for adhering closely to the inner peripheral wall near the upper opening of the liquid passage 47, a flowing-in side seal portion 65 for closing the liquid hole 45 from the upper direction thereof and an air-hole seal portion 66 for closing the air hole 46 from the upper direction thereof. The tip end of the lid member 61 is provided with a hitching nail 67 to be hitched to the lock member 8 and an engaging piece 68 to be engaged to a lock ring 81 of the lock member 8.

[0025] The lock member 8 comprises a hitching portion 82 at its upper portion and a pressing portion 83 at its lower portion. The middle portion of the lock member 8 is rotatably supported by a horizontal supporting axis 84 provided in the attaching portion 42. The hitching portion 82 is always urged to the closing direction by a spring 85 wound on the supporting axis 84.

[0026] According to the cap body 3 thus constructed, when the pressing portion 83 of the lock member 8 is radially inwardly pressed from the closing state shown in FIG. 2, the hitching portion 82 of the lock member 8 is radially outwardly opened, and the engagement between the engaging portion 82 and the engaging nail 67 of the lid member 6 is released. Then, the lid member 6, as shown in FIG. 1 and FIG. 3, is rotatably opened to the upper direction by the urging force of the torsion spring 7 to thereby make it possible to directly drink the beverage in the container body 2 via the drinking mouth 43 from the liquid hole 45 by inclining the beverage container 1 with setting user's lip on the drinking mouth 43.

[0027] At this time, since the uppermost margin of the drinking mouth 43 is formed in the uppermost position of the upper peripheral wall of the cap body receiving portion 41, visibility of the drinking mouth 43 is improved. Furthermore, the back surface of the lid member 6 doesn't contact user's face to thereby make it hygienic. In addition, since there exists a distance from the liquid hole 45 to the drinking mouth 43, there becomes no such occasion that the beverage in the container quickly flows out, thereby it is possible to provide user with relief feeling. Furthermore, even if the beverage container is shakened due to a vibration when user drinks the beverage in container while getting on a vehicle, since the opening area of the liquid hole is narrow and there exists a distance between the liquid hole 45 and the drinking mouth 43, there becomes no such occasion that a large amount of beverage in the container flows out. Moreover, since an opening area of the liquid hole 45 is narrower than those of prior arts when hot beverage is put in the container body 2, a pressure applied to the inner cap 62 of the lid member 6 becomes smaller and then, there becomes no such occasion that the lid member 6 is vigorously released when the lid member 6 is opened.

[0028] Next, hereinafter, the present invention will be explained in detail based on the drawings of the second embodiment where a cap body of a beverage container comprises heat-insulating construction. FIG. 4 to FIG. 7 show the second embodiment of the present invention. A beverage container 11, of a size capable of holding with one hand, comprises a container body 12 of a metallic dual heat-insulating construction, a synthetic-resin cap body 13 releasably mounted in a mouth portion of the container body 12. Since the container body 12 is such constructed that a metallic inner container 121 and a metallic outer container 122, where upper portions thereof are opened, are integrally joined at upper ends thereof, and a heat-insulating portion 123 of a vacuum heat-insulating construction is provided between the containers 121, 122. Furthermore, the outer periphery of the mouth portion of the container body 12 is formed with a screw portion 124 threadably connecting the cap body 13.

[0029] The cap body 13 comprises a cylindrically-shaped shoulder member 14 releasably attached at the mouth portion of the container body 12 and a lid member 17 connected to the shoulder member 14 via a hinge axis 16 for opening and closing an upper opening portion of the shoulder member 14.

[0030] The shoulder member 14 comprises an attaching portion 141 threadably connected to the screw portion 124 of the container body 12, a cap body receiving portion 142 assembled with the attaching portion 141 to be inserted into the inner periphery of the mouth portion of the container body 12. The attaching portion 141 is formed with a hinge axis supporting portion 143 at its one side so that the central portion of a hinge axis 16 is supported by the hinge axis supporting portion 143. Furthermore, a position diametrically against the hinge axis supporting portion 143 is formed with a lock member 18 for maintaining the lid member 17 in a closing state. The cap body receiving portion 142 is formed as a bottomed-cylindrical shape and results from respectively forming a drinking mouth 144 by making the peripheral wall of the upper opening of the lock member 18 side higher, a liquid hole 146 in the drinking mouth 144 side of a bottom wall 145 where the hinge axis supporting portion 143 side thereof is made higher and the drinking mouth 144 side thereof is made lower, and an air hole 147 in the hinge axis supporting portion 143 side, to thereby form a liquid passage 148 from the bottom wall 145 to the upper opening. Furthermore, a lower outer periphery is formed with a packing 149 adhering closely to the inner peripheral wall of the mouth portion of the container body 12.

[0031] The hinge axis supporting portion 143, as shown in the cross-sectional view of FIG. 4, is integrally and continuously formed with the upper portion of the attaching portion 141 to be an approximate cylindrical shape in its cross-sectional plane, and has a horizontal hinge axis inserting hole 151 at the central portion thereof. The hinge axis supporting portion 143 is such formed, that when a radial dimension from the hinge axis inserting hole 151 to the outer periphery may be divided as a front half portion over which the lid member 17 rotates into the opening direction and a rear half portion, the rear half portion is made to have a larger radius, to thereby form a protrusion portion 152 on the outer periphery thereof. That is to say, a radial dimension R2 from the hinge axis inserting hole 151 of the rear half portion to the outer periphery is made larger than a radial dimension R1 from the hinge axis inserting hole 151 of the front half portion to the outer periphery, and the protrusion portion 152 is such formed that the radial dimension thereof becomes gradually lager from the starting end side toward the rear side thereof. Moreover, the tip end of the starting end side of the protrusion portion 152 is made as a sharpened triangle shape.

[0032] In both sides of the hinge axis supporting portion 143, the hinge axis 16 is wound with a torsion spring 19 urging the lid member 17 into the opening direction.

[0033] The lid member 17 comprises a lid portion 171 covering the upper opening of the cap body receiving portion 142 and an inner cap 172 provided in the lid portion 171 to be inserted into the liquid passage 148. The lid portion 171 is formed at its one side with hinge axis receiving portions 173, 173 for respectively supporting the both ends of the hinge axis 16, and the middle portion between the hinge axis receiving portions 173, 173 is formed with an inserting concave portion 174 for the hinge axis supporting portion 143. The inserting concave portion 174 establishes a depth of an inner end portion 175 such that the inner end portion 175 lineally contacts the protrusion portion 152 of the hinge axis supporting portion 143 in the opening operation of the lid member 17. Moreover, in a position diametrically against the inserting concave portion 174, the lid portion 171 is formed with a hitching portion 176 to be hitched to the lock member 18. The inner cap 172 is provided with a seal member 177 for sealing the liquid hole 146 and the air hole 147 in a closing state.

[0034] The lock member 18 is rotatably supported by a horizontal supporting axis 181 provided in the attaching portion 141. An upper portion of the supporting axis 181 is provided with a hitching portion 182, and a lower portion thereof is provided with a pressing portion 183 respectively. The hitching portion 182 is always urged into the closing direction by a spring 184 wound on the supporting axis 181.

[0035] According to the cap body 13 thus constructed, when the pressing portion 183 of the lock member 18 is pressed, the hitching portion 182 is outwardly opened, and the engagement between the hitching portion 182 and the hitching portion 176 of the lid member 17 is released. Then, the lid member 17 is upwardly rotated about the hinge axis 16 to be opened by the urging force of the torsion spring 19. At this time, in a step that the lid member 17 is opened to be rotated from its upright state to the rear direction, the inner end portion 175 of the inserting concave portion 174 of the lid member 17 lineally and slidably contacts the protrusion portion 152 of the hinge axis supporting portion 143. Since the tip end of the starting end side of the protrusion portion 152 is formed as a sharpened triangle shape, a contact area between the protrusion portion 152 and the inner end portion 175 increases according to the opening operation of the lid member 17. Thus, a speed toward the opening direction of the lid member 17 decreases and then, the rotation of the lid member 17 is stopped before it collides with the shoulder member 14.

[0036] Therefore, an impact force in the opening operation of the lid member 17 is alleviated, and an unpleasant impact is not applied to user's hand holding the container body 12. Furthermore, since there become no need to consider strength of the urging force of the torsion spring 19, it is possible to improve a degree of freedom in selecting the torsion spring 19 to thereby decrease the manufacturing cost. Moreover, there becomes no such problems that the urging force of the torsion spring 19 is too weak for the lid member to be sufficiently opened, or that the lid member 17 falls down due to failing to sustain its weight or inclining strength when the beverage container is inclined for drinking.

[0037]FIG. 8 shows the third embodiment of the present invention where a radial dimension from a hinge axis inserting hole 151 of a protrusion portion 152 at the hinge axis supporting portion 143 to an outer periphery is such formed that a radial dimension R3 of a rear end side is gradually larger than a radial dimension R2 of a starting end portion thereof. Thus, in the opening operation of the lid member 17, as the rotation of the lid member 17 becomes larger, the inner end portion 175 of the lid member 17 strongly, lineally and slidably contacts the protrusion portion 152 of the hinge axis supporting portion 143, thereby the rotation of the lid member 17 is stopped before it collides with the shoulder member 14.

[0038] Therefore, it is possible to establish a rotation-stopping position of the lid member 17 by considering changing the dimension from the radial dimension R2 of the starting end side of the protrusion portion 152 toward the radial dimension R3 of the rear end side thereof. Moreover, it is possible to cope with such a case even that a depth of the inner end portion 175 of the lid member 17 is changed due to assembling error.

[0039]FIG. 9 and FIG. 10 show the fourth embodiment of the present invention. In this embodiment, similar to the second embodiment of the present invention, is characterized in that a tip end of a starting end side is formed as a sharpened triangle shape. Protrusion portions 178, such formed that a radial dimension from a hinge axis inserting hole 151 toward an outer periphery is made to be gradually larger over a rear half portion, are respectively formed in the hinge axis receiving portions 173, 173 of the lid member 17 such that the respective protrusion portions 178 lineally and slidably contact the upper margin of the shoulder member 14 in the opening operation of the lid member 17. By such constructions, it is also possible to achieve the same effects as the previously-mentioned embodiments of the present invention.

[0040] As described above, since according to the present invention, the cap body comprises a cylindrically-shaped drinking mouth member releasably provided in a mouth portion of a container body; a lid member connected to the drinking mouth member via a hinge axis; a spring for urging the lid member to the opening direction; and a lock member provided in a position against the hinge axis of the drinking mouth member for maintaining the lid member in a closing state, wherein the drinking mouth member comprises a drinking mouth formed in the lock member side of a peripheral wall of the upper opening; a bottom wall where the drinking mouth side thereof is made lower and the hinge axis side thereof is made higher; a liquid hole formed in the drinking mouth side and an air hole formed in a hinge axis side on a connection line between the hinge axis side of the bottom wall and the lock member side, and the lid member comprises an inner cap provided with a seal member for sealing the liquid hole and the air hole, and since there exists a distance from the liquid hole to the drinking mouth, there becomes no such occasion that the beverage in the container quickly flows out thereby it is possible to provide one with relief feeling. Furthermore, even though the beverage container is shakened due to a vibration or the like when one tries to drink the beverage in the container while getting on a vehicle, since the opening area of the liquid hole is narrow and there exists a distance from the liquid hole to the drinking mouth, there becomes no such occasion that a large amount of beverage flows out. Moreover, since an opening area of the liquid hole becomes narrower than prior arts when hot beverage is put into the container body, a pressure applied to the lid member is smaller thereby there becomes no such occasion that the lid member is vigorously released when the lid member is opened. In addition, by forming the uppermost margin of the drinking mouth in the uppermost position of the upper peripheral wall of the drinking mouth member, it is possible to improve the visibility of the drinking mouth, and the back surface of the lid member doesn't contact one' face to thereby make it hygienic in drinking beverage.

[0041] Moreover, according to the present invention, since the cap body of the beverage container connects a cylindrically-shaped shoulder member releasably provided in a mouth portion of a container body and a lid member for opening and closing an opening portion of the shoulder member by a hinge axis being inserted into a hinge-axis supporting portion of the shoulder member and a hinge-axis receiving portion of the lid member, and since the cap body provides a spring in the hinge axis for urging the lid member to the opening direction, and provides at least one of the hinge axis supporting portion or the hinge axis receiving portion with a protrusion portion to which the lid member or the shoulder member slidably contacts, in an opening operation of the lid member, when the lid member upwardly rotates about the hinge axis to be opened by the urging force of the spring, the lid member or the shoulder member slidably contacts the protrusion portion and a speed to the opening direction of the lid member decreases thereby the rotation of the lid member is stopped before it collides with the shoulder member. Thus, the impact force of the lid member in an opening operation is alleviated, and an unpleasant impact is not applied to one's hand holding the container body. Furthermore, since the urging force of the spring to open the lid member will do only if it is enough to open the lid member, it is possible to improve a degree of freedom in selecting the spring to thereby decrease the manufacturing cost. 

What is claimed is:
 1. A cap body of a beverage container comprising: a cylindrically-shaped drinking mouth member releasably provided in a mouth portion of a container body; a lid member connected to said drinking mouth member via a hinge axis for opening and closing an upper opening of said drinking mouth member; a spring for urging said lid member to the opening direction; and a lock member provided in a position diametrically against said hinge axis of said drinking mouth member for maintaining said lid member in a closing state, wherein said drinking mouth member comprises a drinking mouth formed in said lock member side of a peripheral wall of said upper opening; a bottom wall where said drinking mouth side thereof is made lower and said hinge axis side thereof is made higher; a liquid hole formed in said drinking mouth side and an air hole formed in a hinge axis side on a connection line between said hinge axis side of said bottom wall and said lock member side, and said lid member comprises an inner cap provided with a seal member for sealing said liquid hole and said air hole.
 2. The cap body of the beverage container of claim 1, wherein an uppermost margin of said drinking mouth is formed in an uppermost position of an upper peripheral wall of said drinking mouth member.
 3. A cap body of a beverage container comprising: a cylindrically-shaped shoulder member releasably provided in a mouth portion of a container body; a lid member for opening and closing an opening portion of said shoulder member; a hinge axis being inserted into a hinge axis supporting portion of said shoulder member and a hinge axis receiving portion of said lid member; a spring provided in said hinge axis for urging said lid member to the opening direction; and a lock member provided in a position diametrically against said hinge axis for maintaining said lid member in a closing state, wherein at least one of said hinge axis supporting portion or said hinge axis receiving portion is provided with a protrusion portion to which said lid member or said shoulder member slidably contacts, in an opening operation of said lid member.
 4. The cap body of the beverage container of claim 3, wherein said protrusion portion is such formed that a radial dimension thereof becomes gradually larger toward the opening direction of said lid member.
 5. The cap body of the beverage container of claim 3 or 4, wherein slidable contact between said protrusion portion and said lid member or said shoulder member is linear contact.
 6. The cap body of the beverage container of claim 3 or 4, slidable contact area between said protrusion portion and said lid member or said shoulder member increases according to an opening operation of said lid member.
 7. The cap body of the beverage container of claim 5, slidable contact area between said protrusion portion and said lid member or said shoulder member increases according to an opening operation of said lid member. 